Rapid onset of a Comptonisation zone in the repeating tidal disruption event XMMSL2 J140446.9-251135
We report here on observations of a tidal disruption event (TDE), XMMSL2 J1404-2511, discovered in an XMM-Newton slew, in a quiescent galaxy at z = 0.043. X-ray monitoring covered the epoch when the accretion disc transitioned from a thermal state, with kT ∼ 80 eV, to a harder state dominated by a w...
| Autores: | , , , , , , , , , , , , , |
|---|---|
| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/411589 |
| Acesso em linha: | http://hdl.handle.net/10261/411589 |
| Access Level: | acceso abierto |
| Palavra-chave: | Accretion X-rays: galaxies Accretion disks Galaxies: nuclei Galaxies: individual: XMMSL2 J140446.9–251135 |
| Resumo: | We report here on observations of a tidal disruption event (TDE), XMMSL2 J1404-2511, discovered in an XMM-Newton slew, in a quiescent galaxy at z = 0.043. X-ray monitoring covered the epoch when the accretion disc transitioned from a thermal state, with kT ∼ 80 eV, to a harder state dominated by a warm, optically thick corona. The bulk of the coronal formation took place within 7 days and was coincident with a temporary drop in the emitted radiation by a factor 4. After a plateau phase of ∼100 days, the X-ray flux of XMMSL2 J1404-2511 decayed by a factor 500 within 230 days. We estimate the black hole mass in the galaxy to be MBH = 4 ± 2 × 106 M⊙ and the peak X-ray luminosity LX ∼ 6 × 1043 ergs s−1. The optical/UV light curve is flat over the timescale of the observations with Lopt ∼ 2 × 1041 ergs s−1. We find that TDEs with coronae are more often found in an X-ray sample than in an optically selected sample. Late-time monitoring of the optical sample is needed to test whether this is an intrinsic property of TDEs or is due to a selection effect. From the fast decay of the X-ray emission we consider that the event was likely due to the partial stripping of an evolved star rather than a full stellar disruption, an idea supported by the detection of two further re-brightening episodes, two and four years after the first event, in the SRG/eROSITA all-sky survey. |
|---|